Species

chromosomes

Summary

Summary: In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)

..lysine 9 position is trimethylated and this mark is closely associated with Polycomb binding sites on polytene chromosomes but is also found in centric heterochromatin, chromosome 4, and telomeric sites...

Jonathan A EisenThe Institute for Genomic Research, Rockville, Maryland, United States of AmericaPLoS Biol 4:e286. 2006

..thermophila, which is approximately 104 Mb in length and composed of approximately 225 chromosomes. Overall, the gene set is robust, with more than 27,000 predicted protein-coding genes, 15,000 of which have ..

..we report an efficient, site-specific system of genetic integration into Plasmodium falciparum malaria parasite chromosomes. This is mediated by mycobacteriophage Bxb1 integrase, which catalyzes recombination between an incoming attP ..

..example of a more general mechanism called meiotic silencing of unsynapsed chromatin (MSUC), which silences chromosomes that fail to pair with their homologous partners and, in doing so, may protect against aneuploidy in subsequent ..

..During meiotic prophase, the apparent role of these SUN-domain proteins, together with their partner KASH-domain proteins, is to connect chromosomes through the intact nuclear envelope to force-generating mechanisms in the cytoplasm.

In Xenopus laevis egg extracts, TPX2 is required for the Ran-GTP-dependent assembly of microtubules around chromosomes. Here we show that interfering with the function of the human homologue of TPX2 in HeLa cells causes defects in ..

Meiotic chromosomes have been studied for many years, in part because of the fundamental life processes they represent, but also because meiosis involves the formation of homolog pairs, a feature which greatly facilitates the study of ..

Genome haploidization during meiosis depends on recognition and association of parental homologous chromosomes. The C. elegans SUN/KASH domain proteins Matefin/SUN-1 and ZYG-12 have a conserved role in this process...

The papillomavirus E2 protein tethers viral genomes to host mitotic chromosomes to ensure genome maintenance. We have identified the bromodomain protein Brd4 as a major cellular interacting partner of the bovine papillomavirus E2...

The architecture of interphase chromosomes is important for the regulation of gene expression and genome maintenance. Chromosomes are linearly segmented into hundreds of domains with different protein compositions...

..Chromosome synapsis occurs after CO/NCO designation and is not required for the regulated distribution of COs along chromosomes manifested as CO interference.

Zebrafish hox clusters and vertebrate genome evolution

A AmoresInstitute of Neuroscience, University of Oregon, Eugene, OR 97403, USAScience 282:1711-4. 1998

..Thus, teleosts, the most species-rich group of vertebrates, appear to have more copies of these developmental regulatory genes than do mammals, despite less complexity in the anterior-posterior axis...

Phosphorylation of histone H3 is required for proper chromosome condensation and segregation

Y WeiDepartment of Biology, University of Rochester, New York 14627, USACell 97:99-109. 1999

..NUP-1 knockdown also disrupts organization of nuclear pore complexes and chromosomes. Most significantly, we find that NUP-1 is required to maintain the silenced state of developmentally regulated ..

Synaptonemal complex-dependent centromeric clustering and the initiation of synapsis in Drosophila oocytes

The pairing of homologous chromosomes and the intimate synapsis of the paired homologs by the synaptonemal complex (SC) are essential for subsequent meiotic processes including recombination and chromosome segregation...

..Recent studies have identified more than 80 kinetochore components, and are revealing how these proteins are organized into the higher order kinetochore structure, as well as how they function to achieve proper chromosome segregation...

..only one crossover per chromosome pair per meiosis, by constructing genetic maps of end-to-end fusions of whole chromosomes. Fusion of chromosomes removes the requirement for a crossover in each component chromosome segment and thereby ..

..elegans exhibit different levels of variation less because of their own attributes than because of differences in the effective population sizes of the genomic regions harboring their underlying loci...

..3 variant, which has a conserved N-terminal tail, can replace histone H3 at sites of active transcription, adds a new layer of complexity and possibilities to the regulation of transcription through changes in chromatin structure...

Reconstruction of the vertebrate ancestral genome reveals dynamic genome reorganization in early vertebrates

..the chicken genome, which was not considered in the reconstruction step, and observed that many ancestral proto-chromosomes were retained in the chicken genome and had one-to-one correspondence to chicken microchromosomes, thereby ..

Breakage-fusion-bridge cycles and large insertions contribute to the rapid evolution of accessory chromosomes in a fungal pathogen

..offspring from experimental crosses to show that this pathogen harbors a highly diverse complement of accessory chromosomes that exhibits strong global geographic differentiation in numbers and lengths of chromosomes...

Accurate segregation of chromosomes during meiosis requires physical links between homologs. These links are usually established through chromosome pairing, synapsis, and recombination, which occur during meiotic prophase...

Nuclear genomes of human, animals, and plants are organized into subunits called chromosomes. When isolated into aqueous suspension, mitotic chromosomes can be classified using flow cytometry according to light scatter and fluorescence ..

RNAi components are required for nuclear clustering of Polycomb group response elements

..Both are hypervariable rhoptry proteins that are secreted into the host cell upon invasion. These results suggest that secreted kinases unique to the Apicomplexa are crucial in the host-pathogen interaction...

The medaka draft genome and insights into vertebrate genome evolution

Masahiro KasaharaDepartment of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277 0882, JapanNature 447:714-9. 2007

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A mutant with a defect in telomere elongation leads to senescence in yeast

..In addition, we find that low-copy integrated lines can also be used to express transgenes in the C. elegans germline, where conventional extrachromosomal arrays typically fail to express due to germline silencing...

W F MarshallDepartment of Biochemistry, University of California at San Francisco, San Francisco, California, 94143, USACurr Biol 7:930-9. 1997

Structural studies of fixed cells have revealed that interphase chromosomes are highly organized into specific arrangements in the nucleus, and have led to a picture of the nucleus as a static structure with immobile chromosomes held in ..

Survivin and the inner centromere protein INCENP show similar cell-cycle localization and gene knockout phenotype

Acquisition of knowledge of the nature and DNA content of B chromosomes has been triggered by a collection of molecular techniques, one of which, microdissection, has provided interesting results in a number of B chromosome systems...

Polytene chromosomal maps of 11 Drosophila species: the order of genomic scaffolds inferred from genetic and physical maps

..Despite the conservation of genes within homologous chromosome arms across species, the karyotypes of these species have changed through the fusion of chromosomal arms followed by subsequent rearrangement events...

During interphase chromosomes decondense, but fluorescent in situ hybridization experiments reveal the existence of distinct territories occupied by individual chromosomes inside the nuclei of most eukaryotic cells...

Research Grants71

..mice and controls, and we will examine how Islet1 regulates its target genes by modifying gene structure in chromosomes. Third, we will use a system for induced genetic rearrangement to test the function of Brn3a and Islet1 in the ..

..g. non-synonymous coding SNPs and b) to mask striatal gene expression data. 2) To interrogate two QTLs found on chromosomes 1 and 14 and which have been repeatedly shown to be associated with the catalepsy response...

DESCRIPTION (provided by applicant): During meiosis, homologous chromosomes seek each other out and are then tethered together by the synaptonemal complex (SC) and sister chromatid cohesion, without which homologous recombination and ..

..We will also develop theoretical models for the population dynamics of polymorphic Y chromosomes associated with YRV to determine whether a model based on competitive binding is possible with realistic values ..

..This enzyme is responsible for maintaining the length of telomeres, repeated pieces of DNA at the ends of chromosomes, but it is unknown why this enzyme is expressed at high levels in diseased lungs...

Project Summary During meiosis, homologous chromosomes seek each other out and are then tethered together by the synaptonemal complex (SC) and sister chromatid cohesion, without which homologous recombination and meiotic division cannot ..

..The proposal builds on the progress in the Anderson and Studer labs at i) using modified bacterial artificial chromosomes (BACs) to obtain tissue-specific expression of reporter genes in transgenic mice as well as in mouse and human ..

..nicotine and other natural products - can have profound effects on the replication, segregation, and repair of chromosomes. Moreover, an organism's environment has a strong impact on gene expression patterns...

..One such change is the shortening of telomeres, the caps that protect the ends of our chromosomes. This proposal will study a new component of the enzyme telomerase that is required for maintaining telomeres...

..haploid males, allowing direct expression of alleles and simplifying crosses in the absence of complex marker chromosomes;5) production of highly stable diapausing eggs;5) many closely related strains and species that differ in life ..

..by applicant): In humans, there are two isoforms of clathrin protein, CHC17 and CHC22, named for their encoding chromosomes. The CHC17 isoform is well studied and forms the outer layer of clathrin-coated vesicles, which sort cargo ..

..receptor gene assembly and prevent aberrant interactions that may lead to oncogenic translocations with other chromosomes. PUBLIC HEALTH RELEVANCE: The packaging and spatial organization of DNA in the nucleus are key determinants of ..

..provided by applicant): Telomeres are made up of repeat sequences of nucleotides at the ends of human chromosomes. The function of telomeres is to protect chromosomes from degradation and to maintain their structural ..

..provided by applicant): Three multi-protein complexes scaffolded by members of the Structural Maintenance of Chromosomes (SMC) family of protein are key regulators of chromosome dynamics: cohesin (Smc1/3), condensin (Smc2/4) and the ..

DESCRIPTION (provided by applicant) Aneuploidies or abnormal numbers of chromosomes in a cell, originate from errors in the segregation of chromosomes during the two highly regulated programs of cell division, mitosis and meiosis...

..cancer genome is often highly aneuploid (aberrant chromosome numbers) or polyploid (with aberrant sets of chromosomes), and almost always highly rearranged, with several areas of gains and losses (10)...

..Telomeres are specialized protein-DNA complexes that protect the ends of eukaryotic chromosomes. In most eukaryotes, telomeres contain short DNA repeats that are maintained by the telomerase reverse ..

..chromosome pairing, synapsis and crossing over rely on homology between the paternal and maternal homologous chromosomes to ensure proper segregation and formation of gametes with the correct number of chromosomes...

DESCRIPTION (provided by applicant): Telomeres are stabilizing elements located at the ends of the chromosomes. Telomere maintenance is central to unlimited replication - a key hallmark of the uncontrolled growth of cancer...

DESCRIPTION: The mechanisms by which homologous chromosomes pair with each other remains mysterious; evidence can be mustered to support the existence or non-existence of discrete sites of pairing initiation...

..that prevents the transmission of potentially damaged DNA to the embryo by disruption of the paternal chromosomes that this mechanism is based on the activity of endogenous nucleases, and that it can be active within sperm ..